JPH11198375A - Ink jet recording head and recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control a temperature by a simple manufacturing step of a low cost in an ink jet recording head. SOLUTION: A channel board 3 having an ink channel 6 is fixed to an element board 1 having a heating element 2 and a driving element 8. A circuit board 5 and the board 1 are held by a holding substrate 4 and connected by bonding wires 9. The element 8 is an integrated circuit having a diode sensor and has a temperature sensor function. When the element 8 drives the element 3, an ink in the channel 6 is heated, foamed, discharged from a nozzle 7, and recorded. In this case, the sensor in the element 8 senses a temperature. And, a temperature sensed result is transmitted to a control circuit through the board 5 or the like. The control circuit obtains a recording head temperature from the result and controls driving or the like of the element 2 in response to it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ink jet recording head and a recording apparatus.

[0002]

2. Description of the Related Art Conventionally, as a recording method of a recording apparatus such as a printer, for example, a thermal recording method or an ink jet recording method has been adopted. The thermal recording method is a method in which a heating element is used to apply heat to heat-sensitive paper to form a color, or the ink of an ink ribbon is melted and transferred to a recording medium to perform recording.

The ink jet recording method is a recording method in which ink is ejected from nozzles (ejection ports) provided in an ink jet recording head, and the ink is adhered to a recording material such as paper to perform recording. Very low occurrence,
In addition, since high-speed recording is possible, it has been widely used in recent years. As an ink jet recording head, a head provided with a piezoelectric element and a heating element is known. In particular, it has a heating element, generates bubbles by rapidly heating the ink by applying thermal energy to the ink, and the ink in the ink flow path is ejected from the nozzle as a suitable liquid from the nozzle by volume expansion due to this foaming, A so-called bubble jet type recording head in which ink is introduced from the ink chamber into the ink flow path when bubbles are eliminated has advantages such as good response to a recording signal and easy high density.

In order to form a high-quality image in such an ink jet recording head, it is necessary to keep the amount of droplets ejected for each ink ejection as constant as possible. The amount of discharged droplets depends on the temperature of the recording head. The temperature of the recording head changes due to a difference in duty (duty of a drive signal) according to data to be recorded, a change in environmental temperature, and the like. Therefore, a temperature sensor that detects the temperature of the print head is provided, and the temperature sensor monitors the temperature change, and according to the monitoring result, the heater is heated or the printing speed is controlled, so that the print head is controlled. Conventionally, a configuration is employed in which the temperature is controlled to be constant, and the amount of ejected droplets is made uniform, and the quality of an image is improved.

[0005] Examples of such an ink jet recording head are shown in FIGS. This configuration will be briefly described.
2 are provided on the element substrate 21 provided with a plurality of
Are laminated and fixed, and the heating elements 12 are located in the ink flow paths 16, respectively. The element substrate 21 is provided with a plurality of driving elements 18 for independently driving the heating elements 12, and the ink supply pipes 20A, 20B are connected to ink supply joints 22A, 22A.
The tip of an ink flow path 16 to which ink is supplied via B is a nozzle 17. Stacked element substrate 21
The channel substrate 13 is placed on the holding substrate 14. A circuit board 15 is also provided on the holding substrate 14, and the circuit board 15 and the element substrate 21 are connected by bonding wires 19. And, on the holding substrate 14,
Mounting portions 23 are provided at several locations in the direction of the nozzles 17, and a temperature sensor (thermistor) 24 for detecting the temperature of the recording head is mounted by the mounting portions 23 so as to face the heating element 12. The mounting portion 23 is formed by solidifying a paste having good heat conductivity, and the temperature sensor 2
The heat conduction to 4 is made faster. The temperature sensor 24
Is transmitted to control means (not shown) via the wiring 25 running along the lower surface of the holding substrate 14.

[0006]

According to the conventional example,
Although the temperature of the recording head can be controlled using the temperature sensor 24, the mounting process of the temperature sensor 24 using the mounting portion 23 formed of paste is complicated, and the workability is poor.
Not suitable for mass production, high production cost, and temperature sensor 2
4 itself is expensive.

SUMMARY OF THE INVENTION An object of the present invention is to provide an ink jet recording head and a recording apparatus which can be manufactured at a low cost with a simple manufacturing process and which can control the temperature.

[0008]

The present invention relates to an ink jet recording head in which ink in an ink flow path is ejected from nozzles by applying ejection energy from a plurality of ejection energy generating elements formed on an element substrate, A drive element that drives the discharge energy generation element and functions as a temperature sensor, and is formed as a member separate from the element substrate, is mounted on the element substrate.

The ink ejection operation is controlled based on the result of the temperature detection of the driving element.

The discharge energy generating element is a heating element.

A recording apparatus according to the present invention includes an ink jet recording head having any one of the above-described structures.

This eliminates the need for a temperature sensor as a member separate from the element substrate and the driving element, thereby improving mass productivity and cost. Note that it is possible to directly determine the print head temperature related to ink ejection based on the temperature detection result of the drive element.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 and 2, an element substrate 1 provided with a plurality of heating elements 2 as ejection energy generating means.
The flow path substrate 3 having the ink flow path 6 formed thereon is laminated and fixed, and the heating elements 2 are located in the ink flow path 6, respectively. A plurality of driving elements 8 for independently driving the heating elements 2 are provided on the element substrate 1.
The drive element 8 is electrically connected to the drive element 8 by a not-shown conductive pattern (a wiring pattern of Al or the like formed by a film forming technique). A nozzle (ejection port) 7 is provided at an end of an ink flow path 6 through which ink flows from the ink supply pipes 11A and 11B via the ink supply joints 10A and 10B. The laminated element substrate 1 and flow path substrate 3
It is fixed on the holding substrate 4. A circuit substrate 5 is also fixed to the holding substrate 4, and the circuit substrate 5 and the element substrate 1 are connected by bonding wires 9. Circuit board 5
, An electric signal is transmitted / received to / from a control unit (not shown) via a print cable (not shown) or the like. Therefore, electrical conduction is provided from the control means to the heating element 2 via the printed cable, the circuit board 5, the bonding wires 9, and the drive elements 8 connected to the control means.

The drive element 8 of the present invention has a temperature sensor function. Specifically, an integrated circuit including a diode sensor using the temperature characteristics of a diode is used as the driving element 8 and is directly mounted on the element substrate 1 by a mounting technology such as a clip chip or an ACF. The drive element 8 is mounted so that the circuit formation surface of the drive element 8 faces the heat generation element 2 formation surface of the substrate 1.

Next, the operation of the ink jet recording head will be described.

When a recording signal is supplied from control means (not shown), a print cable (not shown), a circuit board 5,
This recording signal is transmitted to the driving element 8 via the bonding wire 9, and based on the recording signal, the driving element 8
Drives the heating element 2. When the driven heating element 2 generates heat, the ink in the ink flow path 6 becomes hot and foams. At this time, the ink is ejected from the nozzle 7 toward an external recording medium (not shown) due to the volume increase due to the foaming, and the recording is performed. At this time, the diode sensor in the drive element 8 performs temperature detection, and the temperature detection result is transmitted to a control circuit (not shown) via the circuit board 5 and the like. The control circuit stores, as a table in FIG. 3, data associating the detected temperature of the drive element 8 with the print head temperature related to actual ink ejection. Therefore, the control circuit obtains the recording head temperature from the temperature detection result of the driving element 8 having the temperature sensor function,
Based on this, the driving of the heating element 2 (heating temperature, driving frequency, ejection speed, etc.) is controlled, and the recording head is heated by a heater (not shown). During recording, if the temperature detection result changes due to heat generation of the heating element 2 or the driving element 8 itself or a change in environmental temperature, the control is performed in real time. In order to more accurately cope with temperature changes, it is preferable to obtain a relationship as shown in FIG. 3 for each environmental temperature.

According to the present invention, the temperature sensor function can be provided in the same process without changing the manufacturing process of the drive element 8, and the temperature can be controlled without increasing the cost. Since a temperature sensor is provided to face the surface of the element substrate 1, the temperature of the element substrate 1 at a position separated from the heating element 2 can be detected by this sensor.

If the element substrate 1 itself has a temperature sensor function, it is necessary to replace the entire element substrate 1 in the event of a manufacturing defect. In particular, a full line type as shown in FIG. In such an integrated long head, the structure of a large number of driving elements 8 and the heating elements 2 is wasted by only one defect, and the processing for that purpose is also wasted.
However, in the present invention, the driving element 8 mounted on the element substrate 1
Since the device substrate 1 is provided with a temperature sensor function, the element substrate 1 can be used if only the defective drive element 8 is replaced and remounted, which is efficient in terms of the manufacturing process and cost.

[0020]

As described above, according to the present invention,
By detecting the temperature by providing the drive element with a temperature sensor function, the print head temperature can be known, and control can be performed according to the print head temperature. As a result, the amount of discharged droplets can be made uniform, and high-quality recording can be performed stably. In addition, cost and productivity can be significantly improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of an embodiment of an inkjet recording head of the present invention.

FIG. 2 is a partially enlarged cross-sectional view of the ink jet recording head of FIG.

FIG. 3 is a graph showing an example of a relationship between a temperature detected by a drive element and a printhead temperature.

FIG. 4 is a perspective view of a conventional ink jet recording head.

FIG. 5 is a partially enlarged cross-sectional view of the ink jet recording head of FIG.

[Explanation of symbols]

 1, 21 element substrate 2, 12 heating element 3, 13 flow path substrate 4, 14 holding substrate 5, 15 circuit board 6, 16 ink flow path 7, 17 nozzle (ejection port) 8 drive element 9 having temperature sensor function 9, Reference Signs List 19 bonding wire 10A, 10B, 20A, 20B ink supply joint 11A, 11B, 22A, 22B ink supply tube 18 drive element 23 mounting part 24 temperature sensor (thermistor) 25 wiring

Claims (4)

[Claims] 1. An ink jet recording head in which ejection energy is applied from a plurality of ejection energy generation elements formed on an element substrate and ink in an ink flow path is ejected from nozzles, wherein the ejection energy generation elements are driven. An ink jet recording head having a function as a temperature sensor and having a driving element formed as a separate member from the element substrate attached to the element substrate. 2. The ink jet recording head according to claim 1, wherein an ink ejection operation is controlled based on a temperature detection result of the driving element. 3. The ink jet recording head according to claim 1, wherein the ejection energy generating element is a heating element. 4. A recording apparatus having the ink jet recording head according to claim 1.